X4 Pharmaceuticals Appoints E. Lynne Kelley, M.D. as Chief Medical Officer

CAMBRIDGE, MA - Apr 24, 2019 - X4 Pharmaceuticals, Inc. (Nasdaq: XFOR), a clinical-stage biopharmaceutical company focused on the development of novel therapeutics for the treatment of rare diseases, today announced the appointment of E. Lynne Kelley, M.D., FACS, as the company’s Chief Medical Officer (CMO). Dr. Kelley brings more than a decade of experience driving clinical development and global expansion of novel pharmaceutical products at both emerging and established life sciences companies. Dr. Kelley is a Board Certified General and Vascular Surgeon.

“We are thrilled to have Lynne join our team as Chief Medical Officer,” said Paula Ragan, Ph.D., President and Chief Executive Officer of X4 Pharmaceuticals. “Her broad medical and biopharmaceutical industry experience, along with her deep understanding of complex regulatory applications, will be invaluable as we execute our global Phase 3 pivotal trial in WHIM syndrome, a rare genetic, primary immunodeficiency disease, and advance our pipeline across additional rare and ultra-rare diseases.”

“This is an incredibly exciting time for X4 with its many recent accomplishments and ongoing clinical development efforts. I look forward to working with this very talented and dedicated team of industry experts to deliver on a shared goal of bringing novel therapies to patients with rare disease who have limited treatment options,” commented Dr. Kelley.

Before joining X4, Dr. Kelley was CMO of Massachusetts-based biopharmaceutical company Histogenics Corporation (Nasdaq: HSGX), where she led the development of restorative cell therapies to replace damaged cartilage and oversaw the completion of a Phase 3 clinical trial and regulatory submission for the company’s lead program. Dr. Kelley previously served as CMO of Senseonics Holdings, Inc. (Nasdaq: SENS) and held leadership positions in clinical development roles at global companies such as Becton, Dickinson and Company, Kimberly-Clark Corporation, and Boston Scientific Corporation.

Dr. Kelley received her medical degree from Dartmouth Medical School and her bachelor’s degree in biology from Boston University. Dr. Kelley is a fellow of the American College of Surgeons and has authored numerous articles for peer-reviewed publications. She trained at Dartmouth Hitchcock Hospital and Massachusetts General Hospital, and was a practicing surgeon at Yale University. Dr. Kelley was named Fellow of the American College of Surgeons and was awarded an NIH research grant at Harvard and the Marco Polo Fellowship studying at Hospital Henri Mondor of the University Paris Hospital System.

About X4 Pharmaceuticals

X4 Pharmaceuticals is developing novel therapeutics designed to improve immune cell trafficking to treat rare diseases, including primary immunodeficiencies and certain cancers. X4’s oral small molecule drug candidates antagonize the CXCR4 pathway, which plays a central role in immune surveillance. X4’s most advanced product candidate, mavorixafor (X4P-001), is expected to commence a global Phase 3 pivotal trial in patients with WHIM syndrome, a rare genetic, primary immunodeficiency disease, in the second quarter of 2019 and is currently also under investigation in a Phase 2a clinical trial in clear cell renal cell carcinoma. X4 was founded and is led by a team with extensive product development and commercialization expertise, including several former members of the Genzyme leadership team, and is located in Cambridge, Massachusetts.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.  The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.  Forward-looking statements include statements regarding plans for, or progress, scope, cost, duration or results or timing for the initiation, completion or availability of results of development of mavorixafor (X4P-001) or any of our other product candidates or programs, including regarding the Phase 3 clinical trial of mavorixafor for the treatment of patients with WHIM syndrome, the target indication(s) for development, the size, design, population, location, conduct, objective, duration or endpoints of any clinical trial, or the timing for initiation or completion of or reporting of results from any clinical trial, the potential benefits of mavorixafor, or any other product candidate or program or the commercial opportunity in any target indication. These statements are subject to various risks and uncertainties, actual results could differ materially from those projected and X4 cautions investors not to place undue reliance on the forward-looking statements in this press release. These risks and uncertainties include, without limitation, the risk that trials and studies may be delayed and may not have satisfactory outcomes, potential adverse effects arising from the testing or use of mavorixafor or other product candidates, and the risk that costs required to develop mavorixafor or other product candidates or to expand our operations will be higher than anticipated. Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, the risks and uncertainties described in the section entitled “Risk Factors” in X4’s most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC), as updated by X4’s Current Report on Form 8-K filed with the SEC on April 11, 2019, and in other filings X4 makes with the SEC from time to time. X4 undertakes no obligation to update the information contained in this press release to reflect subsequently occurring events or circumstances.

Investors:
Stephanie Carrington
Westwicke, an ICR company
646-277-1282
Stephanie.Carrington@icrinc.com

Media:
Darcie Robinson
Westwicke, an ICR company
203-919-7905
Darcie.robinson@icrinc.com